The present invention relates to heating and air conditioning outlets, particularly heating and air conditioning outlets for vehicles.
In U.S. Pat. 4,644,854, assigned the assignee hereof, and in a number similar patents, air outlets, particularly for vehicles, and more particularly for the defroster outlets, a jet of heated air or defrost air is caused to sweep upon a windshield with the objective being the avoidance of diffusion of the heated air jet prior to impacting on the windshield so that the maximum heat energy is delivered to the windshield. In cases of heating or cooling the interior of the vehicle, air outlets which project a stream of air into the vehicle it is known that a concentrated jet as opposed to a diffused jet "throws" further, that is, it projects further into the space to be heated. See Stouffer U.S. Pat. 4,250,799. In these cases, a fluidic oscillator rhythmically or periodically causes the jet to sweep back and forth at predetermined rates and are used to accomplish these ends. In order to achieve periodic oscillation, the unit disclosed in U.S. Pat. No. 4,644,854 uses a continuous inertance loop connected between the control ports, for example. In Stouffer U.S. Pat. Nos. 4,250,799 and 4,437,392 an air operated oscillator vane is used to periodically oscillate the jet. In some cases, mechanical contrivances such as solenoids, motors and the like (see Kakei U.S. Pat. Nos. 3,745,906 and 3,832,939) have been used to cause the nozzle to sweep back and forth to cause the jet to periodically sweep back and forth into the interior compartment of the vehicle. Movable grates or rotating diffuser grills have likewise been used to cause the directional change of the air into the interior of the vehicle. In all these cases, there is a periodic motion of the jet, caused either by some mechanical contrivance or by fluidic flow phenomena involving no moving parts. Moreover, such prior systems have not been produced in a single-piece molding which is cheaper and can be designed for ease of installation and application to the duct issuing air to the passenger compartment of a vehicle, for example.
Accordingly, an object of the invention is to provide a air outlet which causes aperiodic sweeping movement of the concentrated air jet so as to more efficiently heat or cool the compartment but, at the same time, avoid a continuous jet of air blasting in the same direction, for example, upon an occupant's face or body. Instead of structures which cause a periodic oscillation of the jet, an object of the present invention is to provide a molded outlet fixture which provides aperiodic oscillation of the heated jet and which preferably can be molded in one-piece. According to the invention, an air outlet for a vehicle includes a pair of laterally diverging sidewalls which diverge from each other at a rate or degree sufficient to preclude stable wall effects and for causing aperiodic oscillation of the jet into the passenger compartment of the vehicle.
In a preferred embodiment, the jet issues through an aperture which has off-sets from spaced sidewalls which diverge at an angle greater than about 45 degrees and there is openings provided so as to permit entrainment of ambient air and reduce the time between oscillation or change of direction of the air jet. In a most preferred embodiment, a pair of parallel walls are upstream of the diverging walls and a series of gaps, apertures or holes are provided at the juncture of the parallel walls and the diverging walls with the size of the apertures or holes controlling the dwell time of the jet at each extreme deflection position. Moreover, the downstream outlet aperture may be loaded by a pair of loading vanes so that any attachment effects is rendered quite unstable and the jet sweeps but at a very unperiodic rate.